269
FXUS65 KFGZ 281120
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
420 AM MST Tue Jul 28 2026

.SYNOPSIS...Showers and thunderstorms continue today, before
activity slowly tapers down to isolated coverage later this week and
into the weekend. Once the activity slows down, expect daytime high
temperatures to soar, likely reaching the warmest readings so far
this year, by the weekend.

&&

.DISCUSSION...An impressive convective outburst on Monday evening
has led to the development of a large MCS over northern Mexico and
southeastern Arizona this morning. The MCS is largely decaying, but
still contains decent convective elements. Because of this MCS, a
fairly well-defined MCV is also expected to develop this morning.
This MCV will then track across southern Arizona today and up
through the Lower Colorado River tonight/early Wednesday.

This type of thing ca wreak complete havoc on the forecast. Now, we
must factor in a large amount of debris cloud, how will that inhibit
convection today? It will also drive higher dew points northward for
the remainder of the morning. The entire time this is happening, the
mid-level high to our east temporarily weakens a bit, which will
potentially destabilize the atmosphere, when compared to Monday.

All these factors could easily lead to a more active day today, but
we have rain-cooled air and debris cloud to deal with. Much of the
debris cloud and potential morning showers will affect the southern
portions of our CWA, but the northern zones may very well get that
cherished, sunny start.

The best guess at this time will be for convective showers to move
into the CWA this morning, mainly south of I-40 and into parts of
Yavapai County. Expect a delayed start elsewhere. Conditions north
of I-40, all the way up to the Kaibab, may become quite active by
afternoon, due to the factors mentioned above and the potential for
a warmer and sunnier start.

After today, the high begins to move westward and strengthen, This
slowly introduces drier, mid-level air and subsidence, activity will
slow down. We don`t expect a total stop, but it will be slow through
the weekend. The high may return to a more favorable location by
next week, with easterly steering flow returning, but much can
change in a week and we will see.

Additionally, once the high relocates and strengthens, along with
the Monsoon pause/slow down, temperatures will soar. We expect many
areas to reach the warmest readings so far this year. The various
heat products that have been issued are appropriate.

&&

.AVIATION...Tuesday 28/12Z through Wednesday 29/12Z...Mainly VFR
conditions. SCT SHRA/TSRA through 03Z Wednesday. Greatest coverage
across or near higher terrain features. Brief MVFR/IFR conditions
and gusty, erratic winds in stronger storms. Outside of storms,
expect generally light or terrain driven winds.

OUTLOOK...Wednesday 29/12Z through Friday 31/12Z...Mainly VFR
conditions. ISO-SCT SHRA/TSRA from 18Z-03Z each day, with greatest
coverage across or near higher terrain features. Brief MVFR/IFR
conditions and gusty, erratic winds in stronger storms. Outside of
storms, expect generally light or terrain driven winds.

&&

.FIRE WEATHER...Tuesday and Wednesday...Active Monsoon conditions
are expected today, with a slow downturn beginning Wednesday. Expect
mainly light winds outside of thunderstorms, but trending toward
westerly through southwest 5 to 15 mph over higher terrain. Daytime
temperatures stay around normal, a bit above normal where it does
not rain.

Thursday through Saturday...A continued downturn in Monsoonal
activity is expected through this period, although isolated showers
and thunderstorms remain possible over higher terrain. Temperatures
will rise significantly during this period, with many areas seeing
the warmest conditions so far this year. Winds will be generally
light and variable, at 5 to 15 mph.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

Extreme Heat Warning from 10 AM MST /11 AM MDT/ Friday to 8 PM MST
/9 PM MDT/ Sunday for AZZ005-038, as well as AZZ037 below 4000 feet.

Extreme Heat Warning from 10 AM Thursday to 8 PM MST Sunday for
AZZ006 below 4000 feet.

&&

$$

PUBLIC...Peterson
AVIATION...Peterson
FIRE WEATHER...Peterson

For Northern Arizona weather information visit
weather.gov/flagstaff